1. Field of the Invention
The present invention relates, in general, to apparatus for applying adhesive backed foil onto the edges of stained glass.
2. State of the Art
So-called stained glass articles are formed of numerous small pieces of variously colored glass or plastic which are joined together along adjacent, butting edges to form the desired finished article. Typically, each stained glass piece is edged with a thin strip of metallic foil, such as copper foil, to form a base for the application of lead solder to join adjacent, butted pieces together.
The metallic foil is commonly available in a continuous strip on a roll or spool and has a pressure sensitive adhesive applied to one side or surface to attach the foil to the edges of stained glass. The adhesive is covered by a thin paper backing which is peeled off to expose the adhesive.
As the foil is unwound from the spool and separated from the backing, it is applied to the edge of a piece of stained glass. The width of the foil strip is wider than the thickness of the stained glass such that both edges of the foil strip extend outward over the edges of the piece of stained glass after the foil is initially applied to the edge of the stained glass. The foil edges are subsequently folded over and urged under pressure into contact the adjacent surfaces of the piece of stained glass. Pieces of foil edge stained glass are then butted edge-to-edge and lead solder applied over the foil edges to securely join the stained glass pieces together.
It is well known that the failure to evenly apply the foil to the edges of stained glass pieces frequently results in an uneven distribution of solder once the stained glass pieces are joined together. This results in an undesirable aesthetic finish to the stained glass article and could result in a weak joint between two pieces of stained glass.
The narrow width of the foil and the thinness of the stained glass pieces are major factors in the difficultly in precisely aligning the foil on the edge of a piece of stained glass such that equal amounts of the foil overlap or are folded over both opposed surfaces adjacent to an edge of the stained glass.
The conventional method of applying the foil to stained glass pieces is by hand pressing the foil against the edges of stained glass. In using such a method, the risk of injury from glass splinters in the stained glass pieces is high. Further, the narrow width of the foil and the thinness of the stained glass pieces make it difficult if not impossible to obtain an even distribution of the foil over the entire length of an edge of a piece of stained glass or a foil edge which is not wrinkled or crimped.
In order to alleviate these problems and to insure an even distribution of foil over the edges of stained glass pieces, a variety of tools or applicators have been developed. Such tools or applicators are manually operated devices which typically guide the adhesive surface of the foil as it is unwound from the spool in a channel or other alignment device through which the edge of a piece of stained glass is passed. The channel is designed to evenly align the foil with the piece of stained glass and to provide equal amounts of overlap of the edges of the foil with the piece of stained glass. Such tools or applicators have also be designed with adjustable or variable features to accommodate different foil widths and stained glass piece thicknesses.
However, all such previously devised foil applicator tools require the user to manually urge the piece of stained glass over the foil. An uneven application of force can cause wrinkling or crimping of the foil on the edge of the piece of stained glass. Further, the previously devised foil applicators separate the paper backing from the foil, but do not control the flow or path of movement of the backing after it has been separated from the foil. The separated backing can thus interfere with the application of the foil to the edge of a piece of stained glass.
Thus, it would be desirable to provide a stained glass foil applicator which overcomes the deficiencies found in previously devised foil applicator tools. It would also be desirable to provide a stained glass foil applicator which provides a constant application of force to evenly apply foil to the edge of a piece of stained glass without wrinkling or crimping of the foil. It would also be desirable to provide a stained glass foil applicator which easily and evenly applies foil to the edges of pieces of stained glass. It would also be desirable to provide a stained glass foil applicator which is easier to use than previously devised foil applicators. Finally, it would be desirable to provide a stained glass foil applicator which can be adjusted to accommodate different amounts of foil edge overlap with respect to the edges of stained glass.